Influence of explosion
welding technology
parameters on the titanium
structure
EXPLOSIVE WELDING OF LARGE-SIZE TITANIUM–
STEEL SHEETS: INFLUENCE OF AMBIENT GAS
А. А. Berdychenko, L. B. Pervukhin, and O. L. Pervukhina
TUBULAR ITEMS EXPLOCLAD WITH Ti
O. L. Pervukhina, I.V.Saikov and L. B. Pervukhin
2010
Report plan
1. Influence of ambient gas in technological gap
on the titanium structure.
2. Features titanium structure at its volume
deformation defined by the size of welding
gap.
2
Research technique
1  electric detonator;
2  explosive; 3  clad plate ;
4  base plate ; 5  starting
sensor; 6  shutdown sensor of
the fist frequency meter;
7  shutdown sensor of the
second frequency meter;
8  connecting cables;
9  frequency meters;
10  power supply
1
2
3
4
5
6
7
8
9
R1
R2
R3
10
1  Explosive;
2000
2  electric detonator;
1
2
3  titanium clad plate,
thickness is 5 mm;
3
4
4  titanium bar, thickness is 5
mm;
5
5  titanium base plate,
thickness is 5 mm.
Research methods
1 ,5
10
TEM, X-ray, laser massspectograph
80
3
Air
Vк=3980 m/s.
D=3940 - 1880 m/s
Change of concentration of oxygen СО
(а) и nitrogen СN (б) in metal of vortical
zones
СO,
%
1,5
1
1,0
2
0,5
3
Vк=1880 m/s.
0
0,5
СN,
%
1,5
1,0
А.а.
1,5
L, м
1
1,0
2
0,5
3
0
0,5
1,0
Б.б.
1,5
L, м
1  Vк=3980 m/s; 2  Vк=2640 m/s; 3  Vк=1880 m/s.
4
D=2690 м/с
Nitrogen
Change of gas (Сг)
concentration in a material
of vortical zones of welded
connections received in
the environment of oxygen
(1) and nitrogen (2)
Oxygen
Сг,
%
(вес)
1
1,5
1,0
2
0,5
0
0,5
1,0
1,5
L, м
5
D=2690 м/с
Argon
Helium
Welding in the environment of inert gases of argon and helium considerably improves
structure of welded joint, raises its plasticity and stabilizes quality of welded joint along the
full area regardless of its sizes. The best quality and stability of properties provides with
filling of technological gap with helium.
8
Ti+Steel
The technology of large-size two-layer sheets (Steel + Titanium)
manufacture by explosion welding was developed and patented. The
technical conditions “Two-layer intermediates Steel+Titanium produced
by explosion welding” were formalized and conformed to
Gosatomnadzor. Trumpet lattices of condensers are produced from
two-layer clad in OAO «Kaluga turbine factory ».
7
Ti+Steel
Microstructure Steel 10 + Titanium ВТ1-0 welded by explosion in argon atmosphere.
The beginning of process
Grade of bimetal, Durability of joint, MPa
sizes, mm
Tearing off
Shear
2800 mm from the beginning
of welding process
Tests, degree
Bend
Lateral bend
More 80
More 80
More 80
More 80
9
Problems at manufacture of long-length cylindrical
copper - titanium details by explosion welding :
1. Instability of process at length over 250 mm
2. Occurrence of cracks in clad layer;
3. Formation of intermetallic phases and titanium into a joint
zone.
Choice of technological gap size :
- Thermodynamic conditions of qualitative joint formation (temperature,
pressure, time) must be provided.
- It is necessary to exclude conditions of deformation localization in the
titanium and cracks formation.
- It is necessary to take into account the possible fluctuation of
technological gap in the limits with length of units.
10
Deformation features of a titanium pipe at explosive
compression
Experiments spent on cylinders from
titanium pipe with the size of grain 25
microns.
Explosive
titanium
steel
Length of 70 mm,
external  20 mm, internal  11 mm
R
  0 1
r R
11
Titanium microstructure at different deformations
after shock-wave loading.
Development of a localization strip
The size of grain
Critical parameter
of localization
12
Clad long-length copper bars by a titanium pipe
1. To except cracks formation in Ti the size of technological gap should
provide the relative volumetric cylinder deformation no more than 0,22.
2. To quench a deformation localization in Ti it is necessary to provide
heating of the surface layer to the temperature of plastic state.
1- Copper core
2 - titanium pipe
3 - The top cover
4 - The bottom cover
5 - Technological gap
6 - Explosive
7 - Sand
8 - Detonator
3. To save the
thermodynamic conditions
of explosion welding it is
necessary to except
titanium burning in a gap
by means of its filling with
inert gas.
13
Titanium deformation on the end sites of intermediates
Intermediate Ti+Cu for
a contact jaw
Copper bar
r=0.6.
 25 mm,
l = 1000 mm
Titanium pipe
Change of deformation
mechanism of titanium during
explosive loading is revealed
r=0.6.
wall thickness is 2.5
mm
The relation of
length to diameter
= 33
r=0.1
14
Conclusion:
The experimental technology of long-length Ti+Cu bars
manufacture by explosion welding providing 100% joint
continuity and necessary electrical resistance of joint zone
was developed under the research of deformation features
of titanium pipe and influence of ambient gas in the welding
gap.